Testing machine



May 13, 1969 4 R. J. HERZBERG TESTING MACHINE Sheet Filed 001.. 4, 1965 INVENTOR Rum/0 J- 7 420514 1% 26.03,- ATTORNEY y 3, 1969 R. J. HERZBERG 3,443,422

TESTING MACHINE Filed dot. 4, 1965 Sheet 4 of 2 POWZK INVENTOR. POL/9N0 J. #54 2am;

197 IMA/f/S United States Patent 3,443,422 TESTING MACHINE Roland J. Herzberg, Davenport, Iowa, assignor to Ametek, Inc., New York, N.Y., a corporation of Delaware Filed Oct. 4, 1965, Ser. No. 492,744 Int. Cl. G01n 3/48 US. Cl. 73-81 2 Claims ABSTRACT OF THE DISCLOSURE A hardness testing machine in which the major load will remain constant and be independent of the depth of penetration of the indenter in succeeding operations.

This invention relates to hardness testing machines, and particularly to an improved hardness testing machine in which the major load will remain constant and independent of the depth of penetration of the indenter into the work.

In the testing of specimens for hardness, inaccuracies often occur because the duration of the application of the major force varies from piece to piece. Particularly is this condition noticeable when the hardened case is relatively thin.

The principal object of the present invention is to provide a hardness testing machine in which the major load will remain constant and be independent of the depth of penetration of the indenter in succeeding operations.

Another object of the invention is to provide such a hardness testing machine that will operate correctly with smooth load applications even if the machine is out of lateral plumb.

A further object of the invention is to provide such a hardness testing machine having a power driven timing mechanism for controlling the application of the major load to the work being treated.

In one aspect of the invention, a hardness testing machine may comprise the usual C-type frame construction in which a vertically movable spindle or post is provided for supporting work to be tested.

In another aspect of the invention, the C-frame may include a vertically reciprocable indenter that is moved downwardly by a pivotally mounted power lever.

In another aspect of the invention, the opposite end of the power lever may include a pin adapted to cooperate With a hook assembly, to one end of which assembly a series of replaceable weights may be applied for applying a major load to the Work to be tested.

In a still further aspect of the invention, a pivoted load-supporting lever may include a hooked element adapted to cooperate with the hook assembly for raising the hook assembly 01f the pin on the power lever. This load-supporting pivoted lever may be connected to another pivoted lever having dash pot means connected to it for dampening its movement in either direction.

In a still further aspect of the invention, the last-mentioned pivoted lever may be connected through a toggle joint to a link that is caused to reciprocate by virtue of its connection to a bellcrank lever, which latter is actuated by a handle or depressible bar.

In another aspect of the invention, a timing motor is provide. When the handle is actuated to cause the major weight supporting lever to transfer the major weight onto the main power lever, the timing motor is energized to control the energizing of an unloading motor.

In a further aspect of the invention, the unloading motor may include a cam device adapted to actuate the toggle joint to raise the work-supporting lever to remove the weights from the main power lever.

In a still further aspect of the invention, the unloading motor is adapted to continue to rotate after the removal of the weights from the power lever until the timer cam returns to its starting position.

With the above described arrangement, the time of application of the major load to the specimen will remain constant and is independent of the depth of penetration of the indenter into the specimen.

The above, other objects and novel features of the invention will become apparent from the following specification and accompanying drawings which are merely exemplary.

In the drawings:

FIG. 1 is a sectional elevational view of a hardness testing machine to which the principles of the invention have been applied; and

FIG. 2 is a wiring diagram of the electrical components for the apparatus shown in FIG. 1.

Referring to the drawings, the principles of the invention have been shown as applied to a hardness testing machine including a C-frame 10 of hollow construction. The frame 10 may support a spindle or post 11 in the usual fashion which may be raised and lowered by a hand lever 12, as is well known in the art.

An indenter 13 may be axially aligned with the spindle 11 and be mounted in the Gimme 10 for vertical movement. The upper end of the indenter 13 may include a V14 for cooperation with a knife edge 15 of a force transmitting member 16. The upper end of the member 16 may include a knife edge 17 adapted to cooperate with a V-groove 18 in one end of a power lever 19. Power lever 19 may be pivoted on a pin 20 mounted within the C-frame 10. Its opposite end may include a pin 21 adapted to cooperate with a hook assembly 22. The hook assembly may comprise a hook portion 23 at its upper end and an eye 24 at its lower end. A bar 25 may be connected to the eye 24, and it may be adapted to support removable weights 26 for applying a major load to the power lever 19.

A load-supporting lever 27 may be pivoted on a pin 28 mounted within the C-frame 10, and intermediate its ends it may be pivotally connected to a vertically extending bar 29. A yoke assembly 30, fixed to one end of lever 27, may be adapted to cooperate with a pin 31 on the hook assembly 22 in a manner to provide considerable lateral clearance between it and the yoke 30. This construction makes it possible for the apparatus to operate correctly with smooth load application, even if the machine is out of lateral plumb. This is accomplished by the fact that when the load is hanging on the power lever 19, the hook assembly 22 can seek its own location in the yoke 30, and since pin 31 is freely floating, it can compensate for misalignment in the yoke fingers.

The end of the bar 29 opposite that pivotally connected to the lever 27 is pivotally connected to another lever-32, which latter is pivoted on a pin 33 mounted within the C-frame 10. In order to dampen the movements of the lever 32 and bar 29, a dash pot 34 is provided. It may include a cylinder 35 that is pivotally mounted on a pin 36 supported within the C-frame 10. The cylinder 35 may comprise a piston 37 that is connected to a piston rod 38, the end opposite the piston being pivotally connected at 39 to the lever 32. Valving 40 may be provided for controlling the flow of liquid from one side of the piston 37 to the other side. Thus, with the piston 37 in the position shown in FIG. 1, it is in its upper position and the liquid completely fills the lower portion of the cylinder 35 as well as the upper portion above the piston 37. Movement of bar 29 and lever 32 downwardly causes piston 37 to move downwardly within the cylinder 35, forcing the liquid below it through a passage 41, raising a ball check valve 42 so that it flows through a passage 43 into the cylinder 35 above the piston 37. When the piston 37 moves upwardly within cylinder 35, the liquid above piston 37 flows through passage 43, thence through a passage 44, past a spring check valve 45, thence into the cylinder 35 beneath piston 37.

The end of the lever 32 opposite that pivoted to the pin 33 is pivotally connected by a pin 46 to one link 47 of a toggle link 48. The other link 49 of the toggle link 48 is pivotally connected to a pin 50 within the frame 10. The two adjacent ends of the links 47 and 49 are pivotally connected by a pin 51, and a spring 52 connected between the pins 46 and 50 tends to move the lever 32 downwardly.

Spring 75 is for minor load correction, correcting for minor differences in weight between the indenter assembly and parallelogram formed by bars 76, 77. Sprin 75 will tend to raise the parallelogram assembly.

A horizontal lever 53 has its one end connected to the pivot 51 and its opposite end pivotally connected at 54 to a bellcrank 55, which latter is pivotally mounted at 56 to a support 57 within the frame 10. The bellcrank 55 is connected to a lever 58, the opposite end of which is connected to a handle '59 that is pivoted at 60 within frame An adjusting screw 61 at the end of the lever 53 is adapted to cooperate with a pad 62 for limiting the leftward motion of the lever 53. The construction and arrangement of the tparts are such that mbvement of handle 59 downwardly causes the bellcrank lever 55 to move in a clockwise direction, thereby moving lever 53 rightwardly (FIG. 1) to thereby move the toggle joint 48 beyond dead center, whereupon the spring 52 moves lever 32 and the bar 29 downwardly, thereby to move the yoke from beneath pin 31 so that the major weights 26 are transferred onto the pin 21 of power lever 19.

Lever 27 and bar 29 move downwardly and when the load is fully applied, then switch operator SlA moves away from pin 63 on the hook assembly 22 to close switch S Closing of the switch S energizes a timing motor 64 (FIGS. 1 and 2) that drives a timing cam 65. After a predetermined rotation of the timing cam 65, it closes a switch S thereby energizing unloading motor 66. The unloading motor 66 has a cam 67 connected to its output shaft on which cam a roll 68 is mounted. As the unloading motor 66 rotates, the roll 68 engages a pad 69 that is fixed to the reciprocable bar or lever 53 by pins 70. Engagement between roll 68 and pad 69 forces the lever 53 leftwardly, thereby returning the toggle 48 to the position shown in FIG. 1, raising bar 29 and lever 27, thereby to cause the yoke 30 to engage the pin 31 and raise the weights 26 off the pin 21 of lever 19.

Before the switch S can open by virtue of the raising of bar 29 and lever 27, cam 67 will close switch 8;; which will permit the motor 66 to continue to rotate after switch S is opened to return the timing cam 65 to its initial position, whereupon the cam 67 opens switch S deenergizing the motor 66.

When the machine is actuated by lever 59, the bar 29 moves down, permitting lever 27 to rotate about pin 28. This action causes the weight and hook assembly to be lowered to make contact with pin 21. At this point, the major load has started to be applied to the indenter. When the specimen to be tested has permitted the indenter to be impressed to its maximum depth in keeping with the hardness of the specimen, the power lever and the major load weights will stop moving. The lever 27 will continue down, and at this point the actuator of switch S will move away from pin 63 and start the timer motor.

Although the various features of the improved hardness testing machine have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that changes may be made in such details, and certain features may be used without others without departing from the principles of the invention.

What is claimed is:

1. In a hardness tester, the combination comprising a frame; a spindle mounted in said frame for vertical movement; a vertically movable indenter plunger mounted in said frame in alignment with said spindle; a power lever pivotally mounted within said frame and connected to said plunger; a hook assembly connected to the end of said lever opposite its connection to said plunger; means for supporting weights connected to said hook assembly; a load-supporting lever pivotally mounted in said frame and including a yoke adapted to cooperate with means on said hook assembly for removing said hook assembly from said power lever; means for actuating said load-supporting lever; timing means for resetting said actuating means to remove the load from said power lever; and means for resetting said timing means.

2. In a hardness tester, the combination comprising a frame; a spindle mounted in said frame for vertical movement; a vertically movable indenter plunger mounted in said frame in alignment with said spindle; a power lever pivotally mounted within said frame and connected to said plunger; a hook assembly connected to the end of said lever opposite its connection to said plunger; means for supporting weights connected to said hook assembly; a load-supporting lever pivotally mounted in said frame and including a yoke adapted to cooperate with means on said hook assembly for removing said hook assembly from said power lever; toggle means for actuating said load-supporting lever; handle means for actuating said toggle means; timing means for resetting said toggle means to remove the load from said power lever; and means for resetting said timing means.

References Cited UNITED STATES PATENTS 1,478,621 12/1923 Smith et al. 7381 1,646,195 10/1927 German 73-81 1,752,964 4/1930 Prange 7381 RICHARD C. QUEISSER, Primary Examiner.

C. I. McCLELLAND, Assistant Examiner. 

